The osmotic relations of the plankton diatomDitylum brightwelli(West.)

Abstract

During resting spore formationDitylumloses the cell sap and the volume of the resulting resting spore is one-third to one-twentieth of the cell volume.Ditylum plasmolyses in 3·5–I.7% NaCl solutions, and in a few seconds the protoplast is reduced to the size and structure of a resting spore. In 0·5% NaCl there also occurs a considerable reduction in volume. The plasmolysed cells recover completely when removed into sea water. Rapid plasmolysis was also observed in isotonic and hypotonic dextrose and sucrose solutions and in solutions of CaCl2.